Changes of cardiac output (Q) and stroke volume (SV) were registered in three men of different performance level (high-level cross-country skier, master-skier and leisure athlete) during step-vise increased ergometric work-load up to the exhaustion. Q and SV values were calculated from the continuosly measured VO2 values.
Similarly, values of Qmax and SVmax in four groups of male subjects of different performance level were evaluated. Indirect method of non-invasive estimation of Q and SV can extend the scale of valuable parameters characterizing economy of heart activity.